Putting a Sugar on the Nanoparticle Steering mRNA Delivery Towards Dendritic Cells

This application covers bi-functional lipid compounds, the lipid nanoparticles built from them, and kits for making them, designed so that the particle carries both a lipid tail that anchors it in the membrane and a targeting group that steers it towards a chosen tissue or cell type. The applicant is Rock BioMedical, Inc., a Taiwanese glycoengineering company.

The Problem

Lipid nanoparticles became famous during the COVID-19 pandemic as the delivery vehicle that made mRNA vaccines possible. Naked mRNA is fragile, degrades quickly and does not cross cell membranes on its own. Wrapping it in a lipid shell solved the stability and the entry problem in one step.

What it did not solve is aim. A conventional lipid nanoparticle is assembled from several lipid types in ratios that require careful tuning, and after all that tuning it still goes broadly where the bloodstream takes it, which for intravenous dosing means substantially the liver. The specification is direct about this: lipid nanoparticles generally cannot deliver mRNA molecules with much localised selectivity.

For a vaccine, that is a real cost. The cells you most want to reach are dendritic cells, the professional antigen presenters that take up a foreign protein and show it to T cells, initiating the adaptive immune response. Delivering to them specifically should produce a stronger response from a smaller dose. Delivering everywhere and hoping some lands in the right place is what current practice amounts to.

What This Invention Does

The disclosure defines a bi-functional compound for forming a lipid nanoparticle, set out as two chemical formulae. In both, one arm carries a substituted or unsubstituted glycosyl group, a sugar, and the other carries long chain alkyl, alkenyl or alkynyl groups, or aryl and heterocyclic variants, which act as the lipid tail. The tail buries itself in the bilayer of the nanoparticle. The sugar sits on the outside as the targeting moiety.

Sugar recognition is a real biological addressing system rather than an arbitrary tag. Dendritic cells display C-type lectin receptors that bind particular carbohydrate structures with useful specificity, so a particle presenting the right glycan is preferentially taken up by them.

The formulation claims specify the compound at one to ten mole percent of the composition, which reflects the practical point that only a small fraction of the lipid content needs to be the targeting species. The remainder is conventional lipid. The application also covers kits for preparing these particles, which matters for a platform intended to carry different payloads rather than one fixed product.

Key Features

• Bi-functional lipid compound. A single molecule combines a lipid tail for membrane incorporation with a targeting group for selective delivery.
• Glycosyl targeting moiety. The targeting arm is a substituted or unsubstituted sugar group, exploiting carbohydrate recognition receptors on target cells.
• Two defined chemical formulae. The claims set out two scaffolds with substituent ranges for the alkyl, alkenyl, alkynyl, aryl and heterocyclic groups.
• Low mole percent inclusion. The targeting compound makes up one to ten mole percent of the formulation, leaving the bulk as standard lipid.
• Dendritic cell selectivity. The stated application is selective delivery to a desired tissue region or cell type, including dendritic cells.
• Kits for preparation. The disclosure covers kits for making the nanoparticles, supporting use as a platform across payloads.

Who Is Behind It

The applicant is Rock BioMedical, Inc., a Taipei based biopharmaceutical company working on glycan modulation to improve vaccines and antibody drugs, whose glycoengineered influenza vaccine candidate combining modified mRNA with dendritic cell targeting lipid nanoparticles won the inaugural Moderna Taiwan mRNA Innovation Award in 2023. The named inventors are Jeng Shin Lee, Chi-Huey Wong, Chen-Yo Fan, Chung-Yi Wu and Szu-Wen Wang. Chi-Huey Wong is a prominent carbohydrate chemist, a former President of Academia Sinica and a long standing figure in glycoscience, which explains the sugar centred approach.

The application is a divisional of Australian application 2024252371, the national phase entry of PCT/US2024/023590 published as WO 2024/215614, and claims priority from three United States provisionals filed between April 2023 and April 2024.

Why It Matters

The first generation of mRNA products proved the modality works. The second generation is largely about control: less dose, fewer side effects, and delivery to the cells that matter rather than to whatever the circulation reaches first. Targeted lipid nanoparticles are one of the most actively pursued routes to that, and a good deal of intellectual property is being filed around it.

Using glycans as the address is a distinctive choice. Antibody fragments and peptides are the more common targeting ligands, and both add cost, manufacturing complexity and potential immunogenicity. A small sugar attached to a lipid is cheaper to make, more stable and less likely to provoke an unwanted response against the vehicle itself.

The commercial stakes go beyond vaccines. If a formulation can be aimed at a chosen cell type, the same platform carries gene editing cargo, siRNA and protein replacement therapies to tissues that are currently hard to reach. That is a considerably larger market than seasonal vaccination.

Related Concepts

• Lipid nanoparticle – the delivery vehicle this chemistry modifies.
• Dendritic cell – the immune cell the particles are aimed at.
• Glycobiology – the study of sugars in biology that underpins the targeting strategy.
• C-type lectin receptor – the carbohydrate binding receptors that give the sugars their address function.
• mRNA vaccine – the application area that made this delivery problem urgent.
• Academia Sinica – the Taiwanese research academy connected to several of the named inventors.

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AU 2026202066 was published in the Australian Official Journal of Patents on 9 April 2026 and is open for public inspection. Patent applications represent inventions that are sought to be protected and do not necessarily reflect commercially available products.